Planar microlens array and method of manufacturing same

Abstract

A planar microlens array includes an array of convex microlenses made of an ultraviolet-curable synthetic resin having a high refractive index and disposed on a surface of a base glass plate. A cover glass plate is bonded to the array of convex microlenses by an adhesive layer made of an ultraviolet-curable synthetic resin having a low refractive index. A film made of an ultraviolet-curable synthetic resin is applied to a surface of the base glass plate remote from the array of convex microlenses. The film serves to prevent the planar microlens array from being warped when the ultraviolet-curable synthetic resin of the array of convex microlenses and the adhesive layer are cured.

What is claimed is:  
     
       1. A planar microlens array comprising: 
       a base glass plate including a first surface and a second surface;  
       a cover glass plate disposed adjacent said first surface of said base glass plate;  
       an array of microlenses made of an ultraviolet-curable synthetic resin and disposed between said first surface of said base glass plate and said cover glass plate; and  
       a film of an ultraviolet-curable synthetic resin disposed on said second surface of said base glass plate opposite said array of microlenses.  
     
     
       2. A planar microlens array according to  claim 1 , further comprising an adhesive layer bonding said cover glass plate to said array of microlenses, wherein said array of microlenses comprises an array of convex microlenses made of an ultraviolet-curable synthetic resin having a refractive index that is higher than a refractive index of the adhesive layer and being disposed on a flat portion of said first surface of said base glass plate. 
     
     
       3. A planar microlens array according to  claim 1 , wherein said array of convex microlenses comprises an array of convex microlenses made of an ultraviolet-curable synthetic resin having a refractive index that is higher than a refractive index of the base glass plate and being disposed in respective concavities defined in a flat portion of said first surface of said base glass plate. 
     
     
       4. A planar microlens array according to any one of claims  1  through  3 , wherein said film is made of a material which is the same as the ultraviolet-curable synthetic resin of said array of microlenses. 
     
     
       5. A planar microlens array according to  claim 4 , further comprising: 
       a protective film applied to a surface of said film on said base glass plate and/or a surface of said cover glass plate.  
     
     
       6. A method of manufacturing a planar microlens array comprising: 
       shaping an uncured ultraviolet-curable synthetic resin into an array of convex microlenses between a first surface of a base glass plate and a cover glass plate;  
       forming an uncured ultraviolet-curable synthetic resin into a film on a second surface of said base glass plate opposite said array of microlenses; and  
       exposing to ultraviolet radiation and curing said uncured ultraviolet-curable synthetic resin array of convex microlenses and said uncured ultraviolet-curable synthetic resin film simultaneously.  
     
     
       7. A method of manufacturing a planar microlens array comprising: 
       shaping an uncured ultraviolet-curable synthetic resin into an array of microlenses between a first surface of a base glass plate and a cover glass plate;  
       placing an uncured ultraviolet-curable synthetic resin on a second surface of said base class plate opposite said array of microlenses;  
       laying a protective film over said uncured ultraviolet-curable synthetic resin placed on said second surface of said base glass plate;  
       spreading the uncured ultraviolet-curable synthetic resin placed on said surface of said base plate into a film using a flat surface of a stamper brought into direct contact with said protective film; and  
       exposing to ultraviolet radiation and curing said uncured ultraviolet-curable synthetic resin array of microlenses and said uncured ultraviolet-curable synthetic resin film simultaneously.